DC Offset Blocker/Killer - where to buy in the USA - for MC8207

It appears that the emotive device is using the small internal inductive ring to create a notch filter with the various caps to block all but the 60 hz AC.

The various testing LEDs just let you know the original electrician wired the outlet correctly.....phuphu.

I can therefore see where doubling it up would add a more agressive filtering.

Rod and Patrice are taking a more "elegant" approach......gosh did I hate that description back in engineering classes.
 
https://www.isoteksystems.com/product/get-connected/evo3-syncro/

evo3-syncro-large-1.png
 
I just read through this thread again, it seems a member with a Sansui is having a hum problem similar to this situation.

I was thinking, why on earth don't McIntosh just build this DC blocking circuit into the amplifier, its a known issue with big toroidal transformers? This was they can choose the most effective circuit, granted that in most cases its not necessary, but when it is necessary, it the most valuable part of the equation.

I wonder what happened here, I wonder if the second Emotiva improved the hum at all?
 
Reading Ron C's post I could say arrogance but that might reflect some decades old interactions I had with him and other service issues during the "dark" days, but since non of us are current Mac warranty service stations maybe there is a service bulletin already issued that we are not privy to......neither West's or Patrice's circuits are difficult or expensive just open to liability.
 
Reading Ron C's post I could say arrogance but that might reflect some decades old interactions I had with him and other service issues during the "dark" days, but since non of us are current Mac warranty service stations maybe there is a service bulletin already issued that we are not privy to......neither West's or Patrice's circuits are difficult or expensive just open to liability.
This is exactly what I was thinking, I am sure the liability part is not that difficult to deal with....
I'm going to build one and try it on my Crown to see if it quiets down those big toroidal transformers.
 
Maybe not in NZ but here in the states we have lawyers just looking for a angle.

Are you building Patrice's or Elliot's (sound west) design?
 
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Maybe not in NZ but here in the states we have lawyers just looking for a angle.

Are you building Patrice's or Elliot's (sound west) design?
NZ is getting more like the US with regards to liability, that much we do know.

I haven't decided which one I will build, I will review the designs and make a decision when the time comes.
 
I have McIntosh MC8207, the first unit I bought from an authorized dealer came with a loud buzzing coming from the left transformer, and was replaced with a new unit which came with even a louder buzzing. The buzzing can be heard from 8 feet away. Then I was told to have install new 20 amp outlet that has its own isolated grounding.
That was done professionally by an electrician who installed two isolated 20 amp outlets, two 20 amp circuit breakers, two copper polls for grounding for each outlet, each outlet has its own neutral and power line. After all this done the buzzing sound was still there.
I was then told to buy a power conditioner which I did (Audio Quest Niagara) which was like $4000 and that did not help. Called back McIntosh and was told that I might have DC offset in my AC line and was told by McIntosh that I would need a DC Offset Blocker/Killer to which when I asked them where to buy one they told me to go on the internet and search to find one, to which I cannot find one.
This bothers me a little bit, if you as a company think that I have dc in my ac and i need a dc blocker wouldn't you need to sell one as well. I brought this amp to my friends house and it was the same no improvement, so my guess is that he has dc in the ac line as well.
So If anyone of you knows where to buy a DC Offset Blocker/killer please let me know, but even if this helps kill the buzzing wouldn't you guys think that this expensive somewhat hifi amp/brand should be silent from the factory. I mean this is two units in a row all purchased brand new.

My house is 5 years old, everything is brand new, the whole neighborhood is about 8-9 years old, my electrician says that I have perfect power coming to the house and everything looks fine.

Thank You
Right around the time this was happening Plightron Transformer company was bought by A different company. Funny thing some were good some not so good.Dont know how they passed being tested ????
 
Rod Elliot, within his website ESP ( Elliot Sound Products) wrote a article back in March 2008 about a blocking filter to control DC causing havoc with toriod transformers.......so the issue has been known by engineers using large toriods for years.

It would seem that Mac engineers either did not do due diligence in researching this issue when they choose to begin using this style of transformer or tone deaf to certain dealer and customer problems.

This is hard to say but during the management merry go round and the shift from being a middle America manufacturing company to a big city marketing plan, there seems to be a growing gap in service......I can not help but admit that this is influenced by sales meetings with Gow decades ago as well as one on one conversations with fellow PARA members, again years ago.

I know I am being old school but when I worked for a Mac dealer years ago you could feel the undercurrents begining and if just part of the frustration this particular owner was feeling and expressed within multiple forums is true there are major problems.
 
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